/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package com.feilong.lib.org.apache.http.impl.conn;

import java.net.InetAddress;

import com.feilong.lib.org.apache.http.HttpException;
import com.feilong.lib.org.apache.http.HttpHost;
import com.feilong.lib.org.apache.http.HttpRequest;
import com.feilong.lib.org.apache.http.ProtocolException;
import com.feilong.lib.org.apache.http.annotation.Contract;
import com.feilong.lib.org.apache.http.annotation.ThreadingBehavior;
import com.feilong.lib.org.apache.http.client.config.RequestConfig;
import com.feilong.lib.org.apache.http.client.protocol.HttpClientContext;
import com.feilong.lib.org.apache.http.conn.SchemePortResolver;
import com.feilong.lib.org.apache.http.conn.UnsupportedSchemeException;
import com.feilong.lib.org.apache.http.conn.routing.HttpRoute;
import com.feilong.lib.org.apache.http.conn.routing.HttpRoutePlanner;
import com.feilong.lib.org.apache.http.protocol.HttpContext;
import com.feilong.lib.org.apache.http.util.Args;

/**
 * Default implementation of an {@link HttpRoutePlanner}. It will not make use of
 * any Java system properties, nor of system or browser proxy settings.
 *
 * @since 4.3
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
public class DefaultRoutePlanner implements HttpRoutePlanner{

    private final SchemePortResolver schemePortResolver;

    public DefaultRoutePlanner(final SchemePortResolver schemePortResolver){
        super();
        this.schemePortResolver = schemePortResolver != null ? schemePortResolver : DefaultSchemePortResolver.INSTANCE;
    }

    @Override
    public HttpRoute determineRoute(final HttpHost host,final HttpRequest request,final HttpContext context) throws HttpException{
        Args.notNull(request, "Request");
        if (host == null){
            throw new ProtocolException("Target host is not specified");
        }
        final HttpClientContext clientContext = HttpClientContext.adapt(context);
        final RequestConfig config = clientContext.getRequestConfig();
        final InetAddress local = config.getLocalAddress();
        HttpHost proxy = config.getProxy();
        if (proxy == null){
            proxy = determineProxy(host, request, context);
        }

        final HttpHost target;
        if (host.getPort() <= 0){
            try{
                target = new HttpHost(host.getHostName(), this.schemePortResolver.resolve(host), host.getSchemeName());
            }catch (final UnsupportedSchemeException ex){
                throw new HttpException(ex.getMessage());
            }
        }else{
            target = host;
        }
        final boolean secure = target.getSchemeName().equalsIgnoreCase("https");
        return proxy == null ? new HttpRoute(target, local, secure) : new HttpRoute(target, local, proxy, secure);
    }

    /**
     * This implementation returns null.
     *
     * @throws HttpException
     *             may be thrown if overridden
     */
    protected HttpHost determineProxy(final HttpHost target,final HttpRequest request,final HttpContext context) throws HttpException{
        return null;
    }

}
